Yesterday I met Mahmoud Abu Rideh, a Palestinian refugee who has been subject to a control order since 2005. Prior to this, since 2001, he was imprisoned without charge or trial in Belmarsh high-security prison and Broadmoor mental institution. His treatment has driven him to the point where he is fully prepared to take his own life.

Later today, the Law Lords will pass judgment on whether people subjected to control orders in the UK are given a fair trial. It's quite a technical, legal matter, relating to the use of secret information and security-cleared "special advocates". But in Mahmoud Abu Rideh I saw the human side of this story.

Together with colleagues from Amnesty I sat and remonstrated with him, trying to convince him that there is still some hope. I explained that we have issued an urgent action to our supporters, thousands of whom will now be writing to Home Secretary Alan Johnson urging him to lift the control order or allow Abu Rideh to leave the UK.

But he is a truly desperate man. He told me that he already feels dead inside. At one point he even showed us a packet of razor blades and explained how he planned to go to a park and slash the veins in his wrists and throat. At another point he said he wanted to throw himself in front of a Central line train.

Under the terms of his current control order, he is required to stay inside his home for 12 hours a day, and to phone a monitoring company three times a day. Any visitors to his home while he is there must be approved by the Home Office and he is not allowed to have an internet connection in his home. Any breach of these restrictions is considered a criminal offence.

The police frequently arrive at his home, for example if he oversleeps and misses one of the calls to the monitoring company. He told me how he has been humiliatingly strip-searched in front of female security staff; and how terrified his children were when the police would arrive at the flat in the middle of the night.

In fact the impact on his family life has been so great that his wife and children recently left the UK to stay with her mother in Jordan. This has left Abu Rideh even more isolated and, I imagine, has pushed him yet closer to suicide.

All he wants to do is leave the country: he told me that he has given up on the idea of fighting the control order. He wants a travel document so he can travel to another country, any other country.

He told me that he is an innocent man, that he has no links to terrorism. I don't know whether or not he's innocent: what I do know is that he has never been allowed to see or challenge the secret "evidence" against him – the European Court of Human Rights ruled this year that this was a violation of his right to a fair trial. He has never been charged with a criminal offence, nor put on trial. He has had no chance to prove his innocence and the government seems to have no interest in trying to prove his guilt. They are content to leave him in this appalling limbo: clearly not welcome in the UK nor allowed to enjoy the same basic rights as the rest of us, but not allowed to leave.

Lord Carlile, the government's independent reviewer of counter-terrorism legislation, published a report [pdf] recommending that control orders should not be continued indefinitely, and should not normally be used for any longer than two years. Anyone meeting Mahmoud Abu Rideh would see just why Lord Carlile came to that conclusion: that the ongoing and indefinite restriction on his liberty has had a profoundly negative effect on his mental health.

But I left that meeting more determined than ever that we are right to oppose the control order regime in its entirety. That a man could be driven to the point of suicide because our government forces him to live a half-life, with no opportunity to prove his innocence and no explanation for the presumption of his guilt, is nothing short of disgusting. It's a legacy of previous counterterrorism policy that the new home secretary should look into urgently, before it is too late for Mahmoud Abu Rideh.